Security tag &amp; method using a flowable material

ABSTRACT

A method of fabricating a tag includes the steps of applying a first patterned adhesive to the surface of the substrate and applying a first electrically conductive foil to the first patterned adhesive. A portion of the first electrically conductive foil not adhered to the first patterned adhesive is removed and a second patterned adhesive is applied to a portion of a surface area of the tag. A preformed second electrically conductive foil is applied to the second patterned adhesive to adhere the second electrically conductive foil to the surface of the substrate and portions of the first and second electrically conductive foils are electrically coupled to each other to form a tag circuit. A second patterned adhesive can be disposed between the first and second electrically conductive foils.

RELATED APPLICATIONS

This is a utility application based upon provisional application Ser.No. 60/611,349, filed on Sep. 20, 2004 entitled “Security Tags,Apparatus and Methods for Producing Same”, which was based uponprovisional application Ser. No. 60/547,235, filed on Feb. 23, 2004entitled “Security Tags, Apparatus and Methods for Producing the Same.”Applicant hereby claims for this utility application the benefit of thefiling date of the provisional application whose entire disclosure areincorporated by reference herein.

SPECIFICATION Background of the Invention

1. Field of Invention

The present invention relates to security tags and, more particularly,to a process for making an electrical circuit for use in a security tag.

2. Description of Related Art

Security tags are tags that are adapted to reflect electromagneticenergy in order to indicate their presence within a detection zone. Theycan be associated with an item in order to monitor the item. Two commontypes of security tags are resonant inductor/capacitor (LC) circuitbased tags and dipole antenna based tags. Both of these types of tagsrespond to an electromagnetic scanning signal by providing a responsesignal. The response signal is detectable by suitable signal detectionequipment for indicating the presence of a security tag within a scanneddetection region or interrogation zone (sometimes referred to as an“interrogator”). In particular, the tag provides a response signal whenstimulated by the electromagnetic field at a predetermined tagfrequency. A disturbance of the electromagnetic field caused by theresponse signal is detectable by the signal detection equipment that istuned to a predetermined detection frequency and is located in thedetection region or zone. The signal detection equipment can be adaptedto provide an alarm when an un-deactivated security tag is detected,such as commonly accomplished in Electronic Article Surveillance (EAS)applications.

LC Security Tags

LC resonant tags commonly operate in the RF range. The LC circuits ofsuch tags provide a response signal by resonating in response to theelectromagnetic energy applied to them at their resonant frequency. Inorder to detect the presence of an LC based tag in a detection region orzone, the frequency of the electromagnetic energy applied to that regionor zone is swept through a range of frequencies that includes thepredetermined tag frequency. The LC circuit of the tag resonates whenthe swept frequency of the applied energy reaches the predetermined tagfrequency. A security tag of this type is disclosed in U.S. Pat. No.5,861,809, entitled “Deactivateable Resonant Circuit,” issued on Jan.19, 1999 to Eckstein, et al. (Eckstein).

Typically, the LC circuits of LC-based resonant tags are generallyplanar circuits formed of conductor layers and dielectric layers. One ofthe conductor layers includes one plate of a capacitor and a spiralconductor coil forming an inductor disposed upon a surface of adielectric layer. One plate of the capacitor is connected to a proximalend of the coil. A second conductor layer is formed on the opposingsurface of the substrate to serve as the second plate of the capacitor.The substrate thus serves as the dielectric of the capacitor. A throughconnection between the second plate and the distal end of the coilcompletes the fabrication of the inductor/capacitor (LC) resonantcircuit. The two conductor layers can be formed using well knownphoto-etching techniques. Alternately, the conductor layers can beformed by laser cutting or arc cutting techniques as disclosed in U.S.Pat. No. 5,920,290, entitled “Resonant Tag Labels and Method of Makingthe Same,” issued to McDonough on Jul. 6, 1999.

Other patents disclosing similar technology include U.S. Pat. Nos.6,214,444, 6,383,616 and 6,458,465 assigned to Kabushiki Kaisha Miyake(Miyake) which teach a method for making resonant tags in which acircuit-like metallic foil pattern was adhered to a dielectric filmprepared from a liquid resin by a coating process. A circuit-like metalfoil pattern on one side of the dielectric film is aligned with acircuit-like pattern on the other side of the dielectric film so as toform a capacitor. The dielectric film had openings configured similarlyto and aligned with openings in the circuit-like metal foil, wherein theconfiguration of the circuit-like metal foil pattern and the dielectricfilm was generally spiral in configuration.

U.S. Pat. No. 6,618,939 and Publication No. US 2004/0025324, alsoassigned to Miyake, teach a method for making resonant tags wherein ametal foil having a thermal adhesive applied to at least one face isstamped out into a circuit-like shape and adhered to a base sheet. Themetal foil is stamped onto a metal foil portion having a predeterminedshape while being passed through a die roll having a stamping blade witha predetermined shape. A transfer roll is in contact with the die rollto function as a die back-up roll and to hold the metal foil portionobtained by the stamping operation onto the surface of the transfer rollby suction holes formed in the transfer roll. The stamped out metal foilportion is thermally adhered to the base sheet in contact with thetransfer roll by an adhesive roll in contact with the transfer foilthrough the base sheet.

Another patent assigned to Miyake, U.S. Pat. No. 5,645,932, teaches amethod for making resonant tags in which a laminate was fabricated byadhering a metal foil coated with hot-melt adhesive resin film to acarrier sheet such as paper. The metal foil of the laminate was stampedout using a stamping die to provide a predetermined circuit-likepattern. The metallic foil side of the laminate was superposed on asupport such as a plastic film. The circuit-like metallic foil was thentransferred to the surface of the support by heating the circuit-likepattern from the support side of the carrier sheet side.

U.S. Pat. No. 4,730,095 (the '095 patent), assigned to Durgo A G,teaches a method of producing a plurality of equal printed circuits on acommon, planar insulating carrier having an electrically conductinglayer on at least one of its surfaces. The electrical circuits have aspirally arranged conductor trace forming at least one induction coiland at least one capacitor.

In the '095 patent, a plurality of reference perforations are applied tothe insulating carrier using a laser and a conducting layer is appliedto at least one side of the carrier. A portion of the conductive layerhaving the rough contours of a circuit element is removed. The circuitelement can be an inductive coil and the remaining portion of theconductive layer can have a shape and size approximating the outsidedimensions of the coil. Computer controlled lasers are then used toremove further portions of the conductive layer to provide conductivetracks which form the electrical circuit. The electrical values of thecircuit are determined and compared with design values. The electricalvalues can be corrected using the lasers if necessary.

U.S. Pat. No. 4,900,386, also assigned to Durgo A G, teaches a methodfor producing labels incorporating electrical oscillating circuitswherein parts of the circuits are initially punched out of a center areaof a metal web covered by an adhesive. The center area is then coveredby an insulating material web for handling stability in order to punchout the part of the circuit to be located at the outer web area. Acovering foil is laminated onto the metal web and the parts of theCortez to be located on the reverse side are applied onto the insulatingmaterial web and connected electrical to the remainder of the circuit.

This method of fabricating the elements of an LC-based tag has severalproblems. One particularly significant problem is the cost of thesubstrate itself and the design limitations placed on the tag by varioussubstrate requirements. Since the substrate is a structural element thatmust provide most of the structural integrity of the tag, there areminimum requirements on the mechanical strength of the materials thatcan be used to form the substrate. This limits the number of differentkinds of materials that can be used to form substrates. U.S. Pat. No.5,142,270, entitled “Stabilized Resonant Tag Circuit and Deactivator,”issued to Appalucci et al. on Aug. 25, 1992, discloses selectedconsiderations with respect to substrate strength.

Additionally, the requirement that the substrate provide sufficientmechanical strength to the response circuit imposes a requirement thatthe substrate be formed with a minimum thickness. This limits the amountof capacitance that can be provided on a unit area of substrate surface.U.S. Pat. No. 5,682,814, entitled “Apparatus for Manufacturing ResonantTag,” issued to Imaichi, et al. on Nov. 4, 1997, discloses therelationship between dielectric thickness and capacitance. The materialof the substrate must also be capable of withstanding the photo-etchbaths required to form the elements of the LC circuit. This factorplaces additional limitations on the materials that can be used in thedesign of substrates.

Under these circumstances, it may not be possible to optimize thedielectric properties of the substrate when selecting a dielectricmaterial or a dielectric thickness for use as a component of a securitytag. The inability to optimize the dielectric properties of thedielectric materials results in many problems, such as increasedcapacitor size, lower tag yields and hence, increased costs for thefabrication of security tags.

Other problems encountered in forming the elements of an LC-based tagarise from the photo-etching process. For example, the photo-etchingprocess can be slow and quite expensive. An example of a systemattempting to obtain high speed printing of security tags using aphoto-etch process is U.S. Pat. No. 3,913,219, entitled “Planar CircuitFabrication Process,” issued to Lichtblau on Oct. 25, 1975. Fine tuningof the capacitance within an LC-based tag, by adjusting the amount ofconductive material forming a capacitor plate after the initialfabrication step thereof, is disclosed in U.S. Pat. No. 4,369,557,entitled “Process for Fabricating Resonant Tag Circuit Construction,”issued to Vandebult on Jan. 25, 1983.

In addition to the high cost of the photo-etching process itself, thefact that the process requires environmentally unsafe chemicals createsdisposal problems for the spent materials. As will be appreciated bythose skilled in the art, the procedures required to safely dispose ofspent photo-etching materials significantly increase the costs ofproducing security tags. Furthermore, substantial amounts of conductivematerial must be removed by the etching process when forming theconductor layers of the tag. This further increases the costs of thefabrication process as a result of the waste of conductive materialand/or the complications of performing various recovery processes, suchas recovering aluminum, when forming the tags.

An additional area of difficulty encountered when using the prior artmethods for forming security tags is accurate control of the amount ofthe capacitance in the tags. Inaccurate capacitance can result fromvariations in the dielectric constant, variations in the thickness ofthe dielectric material and variations in the alignment of the capacitorplates. The dielectric constant of the material can normally bespecified and accurately provided for the materials used in thefabrication of tags. Additionally, the dielectric constant of a materialcan be tested prior to the fabrication process. Furthermore, thethickness of the dielectric material can normally be controlled byconventional coating technology and tested prior to the fabricationprocess.

Thus, the most common problem in accurately controlling the capacitanceis the alignment of the circuit elements making up the tag. For example,when the second plate of the capacitor is disposed on the second surfaceof the substrate or over the first plate, much care must be taken tomake certain that the second plate is correctly aligned with the firstplate. Failure to align the plates correctly results in inaccuracies inthe amount of capacitance produced since the actual area of overlap ofthe plates determines the capacitance. This causes inaccuracies in thefrequency at which the tag resonates. Often this results in an upwardshift in resonant frequency.

This problem can limit the speed of the fabrication process, increasethe costs of the fabrication equipment and significantly lower the yieldof the tag fabrication process, for example, by causing tolerancebuildup quality control issues in the fabrication process. Furthermore,it is the nature of the capacitor structures formed during the tagfabrication process that small amounts of plate misalignment producelarge variations in the capacitance produced and concomitant largevariations in the resonant frequency of the resulting tags. This problemtends to be worse for stamped circuits than for etched circuits due tothe nature of the substrate and dielectrics involved in the processes.Another problem is that when foil is die cut into a pattern the shearingaction may create beveled geometry rather than a planar geometry nearthe edge of the cut. That is, the shearing action used to cut the foilmay create sharp edges on the foil that may cut into the substratethereby altering capacitance.

Dipole Security Tags

Dipole-based security tags are adapted for operation in the UHF range.The dipole making up such a security tag basically comprises one or moreconductive strips, or stubs, that function as an antenna for receivingenergy from an applied electromagnetic field. When the received fieldenergy has a predetermined dipole frequency the antenna applies theenergy to an associated system (e.g., circuitry) in the security tag toenergize that circuitry. The circuitry energized in this manner can bean integrated circuit chip that is wire bonded to the conductive, dipolestrips. U.S. Pat. No. 5,708,419, entitled “Method of Wire Bonding anIntegrated Circuit to an Ultraflexible Substrate,” issued to Isaacson etal. on Jan. 13, 1998, discloses the use of antenna to energize a systemat a predetermined tag frequency that is primarily dependent on theantenna length.

When the circuitry within a dipole-based security tag is energized byway of the dipole antenna, the circuitry responds by providing areflected signal. The reflected signal from the security tag istransmitted by the antenna thereby disturbing the applied field. Thus, adipole-based security tag in a detection region can be detected bysweeping the frequency of the electromagnetic energy applied to theregion through a range of frequencies that includes the predetermineddipole frequency. Suitable detection equipment detects the disturbanceof the field when the frequency of the applied energy reaches thepredetermined dipole frequency.

It is known to fabricate dipoles for security tags from copper andsilver. For example, U.S. Pat. No. 6,375,780 entitled, “Method ofManufacturing an Enclosed Transceiver,” issued to Tuttle on Apr. 23,2002, teaches forming security tag dipoles from copper and silver ink.U.S. Pat. No. 5,280,286, entitled “Surveillance and IdentificationSystem Antennas,” issued to Williamson on Jan. 18, 1994, teaches etchingcopper foil to form security tag dipoles. However, the use of copper andsilver for security tag dipoles is very expensive.

Security tags can be used in many applications. In one of many examples,security tags can be attached to an item sold in a retail salesestablishment to monitor the location of item and deter theft. In theretail establishment application, equipment, e.g., a transmitter, forapplying an electromagnetic field to a detection region and detectionequipment, e.g., a receiver, for detecting disturbances of the fieldcaused by the presence of security tags can be located at or aroundpoints of exit from the establishment. Such transmitters and receiverscan be combined into a single unit, sometimes referred to as an“interrogator.” Additionally, detection equipment for security tags inretail establishments can be disposed in many other locations on thepremises in order to monitor movement of the item within theestablishment. Security tags are especially useful in cases where verylarge numbers of items must be monitored.

In another example, security tags can be attached to an inventoried itemin a warehouse or an item being shipped from one location to another incommerce. The use of a security tag in this manner can be especiallyuseful in providing inventory control for very large numbers of items.The use of security tags for inventory control is disclosed in U.S. Pat.No. 6,195,006, entitled “Inventory System Using Articles with RFIDTags,” issued to Bowers et al. on Feb. 27, 2001. Furthermore, securitytags can be attached to books, periodicals, audio tapes and like itemslocated in libraries and other institutions that make such itemsavailable for access by the public.

Many methods for attaching a security tag to an item are known. Onemethod is to clip a security tag to the material of the item to bemonitored. The security tag can also be adhered to the material of theitem to be monitored. Additionally, the tag can be clipped onto oradhered to materials associated with the item to be monitored, such aspackaging, advertising or informational materials. However, all of theknown methods for attaching a security tag to an item are costly anderror-prone. The costs of these methods must be borne by the retailersand/or the providers of the goods or services. These costs are inaddition to whatever costs are incurred in packaging, identifying ormaintaining the items, and providing the required promotional orinformational materials for the items.

Many LC security tags must be activated when they are ready for use.Furthermore, they must be deactivated when a sale of an item isconsummated or when they are legitimately removed from an item. Forexample, an LC security tag which is not removed from an item ordeactivated at a point of sale in one establishment may set off an alarmfrom detection equipment located at a second establishment. This canresult in an innocent customer being questioned by personnel at thesecond establishment.

In general, LC security tags are activated and deactivated by shiftingtheir resonant frequency into and out of the frequency range to whichthe detection equipment is tuned. The resonant frequency can be shiftedfor the purpose of activation and deactivation by changing the amount ofcapacitance in the resonant circuits of the tag. U.S. Pat. No.6,025,780, entitled “RFID Tags Which Are Virtually Activated And/orDeactivated and Apparatus and Methods of Using Same in an ElectronicSecurity System,” issued to Bowers on Feb. 15, 2002 discloses such asystem. Another system for shifting resonant frequencies in this manneris disclosed in U.S. Pat. No. 5,103,210, entitled“Activatable/Deactivatable Security Tag for Use with an ElectronicSecurity System,” issued to Rode on Apr. 7, 1992. Additionally, U.S.Pat. No. 4,876,555, issued to Durgo A G, teaches a method for carryingout deactivation using a continuous hole which can be formed by means ofa needle roll and is disposed in the insulating layer of a resonantlabel in the region between two conducting layers.

One method for changing the amount of capacitance in a security taginvolves creating a weakened area between the two plates of a capacitorduring the tag fabrication process. The weakened area creates a higherelectromagnetic field in its vicinity when electromagnetic energy isapplied to the tag at the predetermined frequency. U.S. Pat. No.5,861,809 (Eckstein) discloses another method for changing the frequencyin a security tag. An inductor taught in this patent is formed with adiscontinuity, or gap, causing an electrical open circuit. The opencircuit is closed with a fuse which is secured near the gap and wirebonded to portions of the inductor near the gap. The fuse is melted by acurrent greater than a predetermined level flowing through it in orderto deactivate the tag. A current level which is high enough to melt thefuse can be induced by an external electromagnetic field. Melting of thefuse causes an open circuit condition, which alters the resonantfrequency of the tag.

In another example of changing capacitance to alter the resonantfrequency of a security tag, one of the capacitor plates can be formedwith a dimple protruding from its surface. The dimple provides a shorterdistance between the tip of the dimple and the opposing plate, thanbetween the remaining surfaces of the two plates. When a high level ofelectromagnetic energy is applied to the tag, a voltage in excess of thebreakdown voltage can be created between the tip of the dimple and theopposing plate. This causes the dielectric material to break down,thereby substantially short circuiting the two plates to each other.When the capacitor shorts out in the weakened area, its capacitance goessubstantially to zero and the resonant frequency of the tag is moved outof the range of frequencies being swept by the detection equipment. Sucha dimple for deactivating a resonant tag is disclosed in U.S. Pat. No.5,142,270, entitled “Stabilized Resonant Tag Circuit and Deactivator,”issued to Appalucci et al. on Jul. 8, 1992.

One problem with the known methods for deactivating tags is that a tagmay spontaneously reactivate at a later time. It is believed that onereason why tags reactivate may be that the short circuit between theplates of the capacitor is formed by fragile dendritic structurescreated by the breakdown of the dielectric. The structures providing theshort circuit between the plates can therefore break at a later time,for example, due to flexing of the tag, and restore the high resistancepath between the plates. When this occurs, a security tag that isdeactivated after a legitimate purchase can set off an alarm if aninnocent bearer of the tag inadvertently brings it into a detectionregion.

It is sometimes desirable to activate or deactivate a large number ofsecurity tags at the same time using bulk activation or bulkdeactivation techniques. For example, a manufacturer of security tagscan manufacture a large number of activated tags. If a container of theactivated tags is sold to a retail establishment that is not using acorresponding detection system, they must be deactivated. In anotherexample, an entire container of items having individual security tagscan be legitimately purchased at the same time. It is not uncommon forsuch containers to have dimensions of four feet by eight feet. In eachcase, large numbers of tags at varying distances and orientations mustbe activated or deactivated at the same time. Thus, problems may occurwhen activation or deactivation energy is applied in these examples andtags may not be effectively processed.

Additional references pertinent to the field of security tags include:U.S. Pat. Nos. 4,215,342; 4,260,990; 4,356,477; 4,429,302; 4,498,076;4,560,445; 4,567,473; 5,108,822; 5,119,070; 5,142,270; 5,142,292;5,201,988; 5,218,189; 5,241,299; 5,300,922; 5,442,334; 5,447,779;5,463,376; 5,510,770; 5,589,251; 5,660,663; 5,682,814; 5,695,860;5,751,256; 5,841,350; 5,861,809; 5,864,301; 5,877,728; 5,902,437;5,920,290; 5,926,093; 5,955,950; 5,959,531; 6,025,780; 6,031,458;6,034,604; 6,072,383; 6,087,940; 6,089,453; 6,166,706; 6,208,235;6,214,444; 6,304,169; 6,458,465; 6,618,939. All references cited hereinare incorporated herein by reference in their entireties.

BRIEF SUMMARY OF THE INVENTION

The invention includes a method of fabricating a tag for reflectingelectromagnetic energy for the purpose of indicating the presence of thetag, the tag including a substrate having a surface, the methodincluding the steps of applying a first patterned adhesive to thesurface of the substrate and applying a first electrically conductivefoil to the first patterned adhesive to adhere the first electricallyconductive foil thereto. A portion of the first electrically conductivefoil not adhered to the first patterned adhesive is removed and a secondpatterned adhesive is applied to a portion of a surface area of the tag,the surface area including the surface and the first electricallyconductive trace. A preformed second electrically conductive foil isapplied to the second patterned adhesive to adhere the secondelectrically conductive foil to the surface of the substrate andportions of the first and second electrically conductive foils areelectrically coupled to each other to form a tag circuit. A secondpatterned adhesive is disposed between the first and second electricallyconductive foils. One of the first and second electrically conductivefoils can form a portion of an inductor and a plate of a capacitor, andthe other of the first and second electrically conductive foils can formanother plate of the capacitor. The tag circuit can be an antenna,including a dipole antenna or an integrated circuit.

The invention further includes a tag arranged to reflect electromagneticenergy for the purpose of indicating the presence of the tag, the taghaving a substrate having a surface with a preformed first patternedadhesive disposed over the surface of the substrate and a first layer ofelectrically conductive material having a shape corresponding to adesired final pattern for a first electrically conductive trace securedto the surface of the substrate by the preformed first patternedadhesive, wherein the preformed first patterned adhesive corresponds tothe desired final pattern. A second patterned adhesive is disposed overa portion of a surface area of the tag the surface area including thesurface and the first electrically conductive trace. An electricallyconductive trace is disposed over the second patterned adhesive toadhere the second electrically conductive trace thereto. An electricalconnection is provided for electrically coupling portions of the firstand second electrically conductive traces to form a tag circuit. Atleast one of the first and second electrically conductive traces can bean inductive element and one of the first and second electricallyconductive traces can be a first plate of a capacitive element. Theother of the first and second electrically conductive traces can be asecond plate of the capacitive element. The tag circuit can be an LCresonant circuit. The preformed first patterned adhesive can be aflexographic printed layer.

The invention further includes a tag arranged to reflect electromagneticenergy for the purpose of indicating the presence of the tag, the taghaving a substrate with a surface including a first patterned adhesivedisposed over the surface of the substrate. The first patterned adhesivehas a shape corresponding to a desired final pattern for a firstelectrically conductive trace. The first electrically conductive traceis disposed over the first patterned adhesive to adhere to the firstelectrically conductive trace thereto. A second patterned adhesive isdisposed over a portion of a surface area of the tag the surface areaincluding the surface and the first electrically conductive trace and asecond electrically conductive trace is disposed over the secondpatterned adhesive to indirectly adhere the second electricallyconductive trace to the first electrically conductive trace. Anelectrical connection is provided for electrically coupling portions ofthe first and second electrically conductive traces to form a tagcircuit.

A method for processing a surface of an item and providing anassociation using a surface processing system includes the steps ofreceiving an item having a first identification marking on a surface ofthe item to provide a received item for providing a first identificationsignal in response to a first interrogation signal and applying a secondidentification marking to the surface of the item for providing a secondidentification signal in response to a second interrogation signal. Themethod also includes applying at least one of the first and secondinterrogation signals to the item to provide at least one of the firstand second identification signals and first receiving the at least oneof the first and second identification signals in response to theapplying the at least one of the first and second interrogation signals.A determining of a first association is made in response to the firstreceiving.

The first interrogation signal can be applied to the received item. Thefirst association with the received item is then determined according tothe first receiving of the first identification signal from the receiveditem. The second interrogation signal can also be applied to thereceived item. Second receiving of the second identification signal anddetermining a second association in accordance with the second receivingcan be performed. If at least one of the first and second identificationsignals includes a signal representative of an item level identificationnumber, then the first association is an association between the itemlevel identification number and the item. If the other of the first andsecond identification signals represents an automatic identificationnumber, then the first association is an association between anautomatic identification number and a circuit element. An associationbetween the automatic identification number and the item levelidentification number or an association between the automaticidentification number and the item can also be determined.

The first association is stored in an association database and a furtherinterrogation signal for interrogating at least one of the first andsecond identification markings is provided for providing a furtheridentification signal. The further identification signal is received. Anassociation is selected from the association database in accordance withthe further identification signal to provide a selected association. Theitem is identified in response to the selected association from theassociation database.

In one embodiment, at least one of the first and second identificationmarkings includes visually perceptible indicia, for example a bar code,or a circuit element, for example, a resonant circuit, a dipole or anintegrated circuit. The bar code represents an item level identificationnumber for identifying the item. When one of the first and secondidentification markings is a visually perceptible marking, the other ofthe first and second identification markings can be a circuit element,for example, an RFID circuit or an EAS circuit.

The first and second identification markings can be applied to thesurface of the item substantially simultaneously using a surfaceprocessing device. The first and second identification markings can beapplied using at least two differing surface processing devices disposedwithin the surface processing system. The surface processing device canbe a printing device, for example, a flexographic printing device, forprinting a bar code on the surface of the item. A further marking, forexample, package information, can also be printed on the surface of theitem using the printing device.

A circuit fabrication device integrated with the printing device withinthe surface processing system applies a circuit element using thecircuit fabrication device to provide a fabricated circuit element. Thefabricated circuit element is applied to the surface of the item. Afurther circuit element is fabricated using the circuit fabricationdevice to provide a further fabricated circuit element, and the furthercircuit element is applied to the surface of the item. At least one ofthe fabricated circuit element and the further fabricated circuitelement can include an RFID circuit or an EAS circuit. A response of thecircuit element is measured to provide a measured response signal. Acircuit parameter of the circuit element is adjusted in accordance withthe measured response signal. A capacitance can be adjusted in responseto the measured response signal, for example, by adjusting the alignmentof capacitor plates or by compressing a dielectric layer. An antenna canbe adjusted in response to the measured response signal, for example, byadjusting the length of the antenna. The visually perceptible indiciaare applied to the surface of the item substantially simultaneously withthe fabricating of the circuit element. A patterned adhesive and apreformed circuit element are applied to the surface of the item usingthe circuit fabrication device.

A circuit element disposed on a substrate surface to reflectelectromagnetic energy for the purpose of indicating the presence of thecircuit element includes first and second capacitor plates disposed overthe surface of the substrate in an aligned relationship with each other.The aligned relationship having manufacturing variations in the relativepositioning of the first and second capacitor plates and a dielectriclayer disposed between the first and second capacitor plates. At leastone of the first and second capacitor plates is formed substantiallysmaller relative to the other of the first and second capacitor plates.The at least one of the first and second capacitor plates is disposed ata predetermined offset in at least one planar direction from an edge ofthe other of the first and second capacitor plates. The predeterminedoffset is selected in accordance with the manufacturing variations toprevent variations in the value of capacitance of the capacitor due tothe manufacturing variations.

The at least one capacitor plate of the first and second capacitorplates can be disposed over the other capacitor plate of the first andsecond capacitor plates. The other capacitor plate of the first andsecond capacitor plates can be disposed over the at least one capacitorplate of the first and second capacitor plates. The dielectric can be asubstrate whereby the first and second capacitor plates are disposed onopposing sides of the substrate. In one embodiment, the at least onecapacitor plate of the first and second capacitor plates is disposed ata predetermined offset from two edges of the other capacitor plate ofthe first and second capacitor plates in two orthogonal planardirections. The predetermined offset is selected to provide an alignmentof the first and second capacitor plates wherein the entire surface areaof the at least one capacitor plate of the first and second capacitorplates faces an opposing surface area of the other capacitor plate ofthe first and second capacitor plates regardless of the manufacturingvariations.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements andwherein:

FIG. 1 is a schematic representation of a method for making exemplarysecurity tags of the present invention;

FIG. 2 is an enlarged view of a portion of the schematic representationof FIG. 1 showing a method for applying adhesive for adhering aconductive foil to a substrate in accordance with the present invention;

FIG. 3 is an enlarged view of a portion of the schematic representationof FIG. 1 showing a method for die cutting a conductive foil inaccordance with the present invention;

FIG. 4 is an enlarged view of a portion of the schematic representationof FIG. 1 showing a method for applying adhesive for adhering adielectric and conductive foil to a substrate in accordance with thepresent invention;

FIG. 5 is an enlarged view of a portion of the schematic representationof FIG. 1 showing a method for die cutting a dielectric and a conductivefoil in accordance with the present invention;

FIGS. 6A and 6B are plan views of generally rectangular dipolestructures which can be fabricated in accordance with the presentinvention;

FIGS. 7A-7D are plan views of generally circular dipole structures whichcan be fabricated in accordance with the present invention;

FIG. 8 is a schematic representation of alternate embodiment of themethod for making exemplary security tags of FIG. 1;

FIGS. 9A and 9B are schematic representations of surface processingsystems including a method of the present invention integrated with oneor more further processes;

FIG. 10 is a block diagram representation of billing models for billingthe costs for using the method of the present invention;

FIG. 11 is a schematic representation of a color printing press andsecurity tag fabrication system for applying colored ink patterns andcircuit elements to the surfaces of a substrate in accordance with thesystem and method of the present invention;

FIG. 12 is a schematic representation of an input stage of a securitytag fabrication system for applying circuit elements to a substrate inaccordance with the method of the invention;

FIGS. 13A and 13B show plan and cross-sectional views, respectively, ofa carrier bearing circuit elements for fabricating exemplary securitytags in accordance with the system and method of the present invention;

FIG. 14 shows a schematic representation of an alternate embodiment of afabrication system and method for fabricating exemplary security tags inaccordance with the system and method of the present invention; and

FIG. 15 shows a capacitor for a security tag formed in accordance withthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there is shown a schematic representation of aprocess 120 for fabricating a security tag according to one preferredembodiment of the invention. The process can be used for producing asecurity tag having a dipole and a security tag having an inductor and acapacitor. In order to facilitate an understanding of the tagfabrication process 120, FIGS. 2-5 show enlarged representations ofselected portions of the schematic representation of FIG. 1.

In the tag fabrication process 120, an adhesive material 122 is appliedto a surface 150 a of a substrate to form a first patterned adhesivelayer 122 a. The pattern of the adhesive corresponds to the pattern ofthe particular portion of the component of the tag, e.g., a portion ofthe coil of the inductor, a plate of the capacitor, a dipole antenna,etc. The first patterned adhesive layer 122 a can be applied to thesubstrate 150 by an adhesive transfer device 130. The adhesive transferdevice 130 can be any conventional adhesive transfer device for applyingadhesive images to a surface known to those skilled in the art. Forexample, the adhesive transfer device 130 can be an adhesive transferdevice within a flexographic printing device, a gravure printing device,a letter pressing device, a silk screen or tempo device and so forth.The adhesive transfer device can be detachably secured to the printingdevice or it can be fixed thereto.

The printing or pressing device can also print indicia on the surface150 a substantially simultaneously with the fabrication of a tag. Theindicia can be visible or invisible to the human eye. It can be humanreadable indicia, machine readable indicia, or any other type ofindicia. For example, the indicia can be visible text, and/or graphics,bar codes or a marking printed with an ink that is visible only inultraviolet light, or some other frequency of light. The indicia caninclude, for example, a single marking, a plurality of markings, or aselected color. In this manner, a bar code or other indicia can beapplied to a surface substantially simultaneously with the fabricationof a tag such as an RFID tag on an EAS tag or other circuits or circuitelements.

The substrate 150 can be any polymeric material (such as PET and PE) ora non-polymeric material that can provide the required structuralintegrity for the security tag to function. For example, the substrate150 can be formed of a material such as a corrugated material, laminatedmaterial, coated metal, any type of plastic, including injection moldedplastic and other types of molded plastics and any kind of ceramicmaterial. The substrate 150 can also be a pressure sensitive label or alabel formed of a fibrous material such as paper, cardboard or cloth.

The paper forming the substrate 150 can be densified Kraft. DensifiedKraft is a mix of standard slurry normally used for making traditionalbond, or offset paper. Traditional papers may be varied to includesofter woods and to include cotton additives along with recycled.Corrugated materials, laminated materials, polymers like PET and PEteflon etc. can also be included.

The paper is normally formed using a traditional slurry mix which passesthrough a small opening of the head box onto a wire mesh running at aspeed that matches the gravity feed fluidic deposition onto the wiremesh. The wire mesh retains the pulp, and lets the water pass through.This mesh is of a great distance and therefore the slurry is formed intowet paper substance. It is then pulled from the mesh and sent through anumber of drying systems until the paper reaches its nominal state ofapproximately 5% moisture content. The paper is then rolled up and latercut into sheets for use. A starch coating can be applied to the paper asit is dried. This process ensures that as the paper is used to writeupon it will not act like a sponge. This is done to varying degrees andfor certain applications. The paper also passes through several nippoints, which helps serve the purpose of reaching a specified thickness.The speed of the equipment is varied to achieve changes in density, andeven the fiber type, length, and direction of the fiber lay are variedto achieve different type papers.

For densified Kraft the paper is formed as normal, however, harder woodsmay be used. The key, however, is the ability to super calendar thepaper. This is done with a heated calendar stack. This is a stack oflarge rollers that the paper web is run in and out of making 180-degreeturns until a stack of 20 rollers and turns are made. This creates apaper that is hard and densified. This is normally done with a highlevel of starch applied to create a paper that will soak up a minimalamount of moisture. This paper is structurally stable and superior tonormal papers in this respect. Also due to its density this paper canwithstand higher puncture, sheer and tensile then other papers.

Paper, as it is used for security tags, i.e., making RF labels and RFantennas, is used predominantly as a carrier for the antenna. The needfor a carrier is due to the fact that an antenna such as used for RFIDsolutions is very thin. The antenna will not retain its shape after itis formed due to the lack of the conductive material's integrity. Theantenna is formed to provide for reception of radio waves; if the shapeis not retained, the reception will not be maintained. The paper createsthe ability to form the object and retain its shape. Densified Kraftcreates a better surface due to its stability.

Mechanical factors, such as whether a material is strong enough toprevent shearing during the tag fabrication process 120, aresubstantially the only limitations placed on the selection of thematerial forming the substrate 150, or its thickness. When a flexiblematerial, like cloth, is used as a substrate in a security tag, it maybe necessary to apply a backing to the material in order to provide therequired structural integrity.

The substrate 150 of a security tag fabricated according to the tagfabrication process 120 can be a composite substrate having at least apeelable layer and a carrier layer. The security tag can be fabricatedon the peelable layer of such a composite substrate 150. When thepeelable layer bearing the security tag is peeled from the carrierlayer, it can be associated with or secured to any item. For example,the peelable layer can be provided with an adhesive layer for adhesivelysecuring it to a surface of an item. A resonant tag formed on acomposite substrate including a removable carrier film is disclosed inU.S. Pat. No. 5,902,437, entitled “Method of Making Resonant TagLabels,” issued to McDonough, et. al. on May 11, 1999.

In the tag fabrication process 120, a first conductive foil 132 isapplied to the substrate surface 150 a over the first patterned adhesivelayer 122 a, for example by an unwind roller (as seen most clearly inFIG. 3). The material forming the conductive foil 132 can be anyconductive material. However, in one preferred embodiment, theconductive foil is aluminum. The conductive foil 132 adheres to thesubstrate surface 150 a in the regions where the first patternedadhesive layer 122 a is disposed by the adhesive transfer device 130.

A die cutter 134 cuts or “patterns” the adhered conductive foil 132according to the pattern of the patterned adhesive layer 122 a, e.g.,along its peripheral edges. This action forms a first patternedconductive trace 132 a in the tag fabrication process 120. A trace willbe understood to include any piece of conductive foil, including forexample, conductive foils that can be used as a conductor for conductingcurrent to form all or part of an electronic circuit, a component or awhole of an antenna geometry, an electromagnetic coupling component forelectronic circuitry, an electromagnetic passive director for an antennageometry, an isolation element (a/k/a shielding) for electromagneticpurposes, a structural element for mechanical strength purposes, or afiducial for post process operations. The blades 133 of the die cutter130 are adapted to cut through the conductive foil 132 without damagingthe surface 150 a of the substrate 150. The die cutter 134 can be aconventional rotating die cutter 134 or any other device known to thoseskilled in the art for cutting a conductive foil without cutting ordamaging the substrate 150. For example, the operations performed by thedie cutter 134 can be performed by a laser. The unused portion of theconductive foil 132 which would otherwise constitute waste is recoveredby the method of this invention, e.g., by any type of vacuum device ormechanical removal device known to those skilled in the art. Conductivematerial recovered for reuse in this manner can be recovered by a simplemelting process. The amount of conductive material required to make asecurity tag using the tag fabrication process 120 can be sixty percentless than the amount typically required by conventional photo-etchingtechniques.

The adhesive transfer device 130 and the die cutter 134 cooperate toprovide a processing station 124 of the tag fabrication process 120 forproviding the first patterned conductive trace 132 a. In one preferredembodiment of the invention, the first patterned conductive trace 132 acan be shaped as a dipole. In this embodiment, an adhesive pattern orimage of a dipole is disposed on the substrate surface 150 by theadhesive transfer device 130. An integrated circuit or other circuitrequired by the tag can be applied in a conventional manner.

An integrated circuit inserted in this manner can be any type ofintegrated circuit known to those skilled in the art, including drivencircuits as well as passive circuits. The passive circuits can include afuse for deactivation or for any other purpose, or a non-linearcomponent, such as a diode for making the signature of a circuit moredistinct.

The possible shapes of the dipole and the device for inserting theintegrated circuit on the tag are discussed in more detail below. Whenproviding a dipole using the processing station 124, the conductive foil132 can be any conductive material, especially a metal such as aluminumor copper. In a preferred embodiment, aluminum is used because aluminumis sufficiently conductive and relatively inexpensive.

Referring now to FIGS. 6A and 6B, there are shown two exemplary dipoles146 a and 146 b which can be fabricated in accordance with the tagfabrication method 120. The dipoles 146 a and 146 b are suitable for usein any location on any type of substrate 150, but are especially usefulfor use in areas of a substrate 150 where a rectangular configurationcan make the best use of the available surface area of the substrate150, such as the rectangular substrate regions 150 b. The dipole 146 aincludes the dipole elements 147, 148 for receiving electromagneticenergy at a predetermined frequency and energizing an associatedintegrated circuit 145. The integrated circuit 145 or other electricaldevice for completing the tag can be disposed between the dipoleelements 147, 148 and wire bonded to them using wires 149 in aconventional manner. The predetermined response frequency of the dipole146 a is primarily determined by the combined length of the dipoleelements 147, 148, wherein the length of the dipole 146 a on thesubstrate 150 b can be approximately equal to the wavelength of thepredetermined response frequency.

The dipole 146 b includes the dipole elements 151, 152, which togetherform an S-shape. The effective antenna length of this type of dipoleexceeds the longitudinal dimension of the dipole 146 b because of theS-shape of the dipole elements 151, 152. Other shapes, such as Z-shapescan be used to make efficient use of the available area of thesubstrate. An integrated circuit 153 or other electrical device can bedisposed upon one of the dipole elements 151, 152 and wire bonded to theother dipole element 151, 152 with a wire 154. The integrated circuit153 can also be disposed between the dipole elements 151, 152 and wirebonded to them.

The shapes of the dipole elements making up either of the dipoles 146 aand 146 b as well as the shapes of any other dipole elements suitablefor efficient use of the area of a rectangular substrate region 150 b,can be easily implemented using suitable patterns for the adhesivetransfer device 130 and the die cutter 134 of the tag fabricationprocess 120. Furthermore, the dipole elements making up each of thedipoles 146 a and 146 b can be easily implemented using the tagfabrication process 120 in any length required to provide the resonantfrequencies that are useful in the field of security tag fabrication.

Referring now to FIGS. 7A-7D, there are shown dipoles 160-163 which canalso be fabricated in accordance with the tag fabrication method 120 ofthis invention. The dipoles 160-163 are especially useful in areas ofsubstrate 150 where a circular configuration makes the best use of theavailable surface area of the substrate 150, such as the circularsubstrate regions 160 a. Each of the dipoles 160-163 includes arespective pair of dipole elements 156, 157 for receivingelectromagnetic energy at a predetermined frequency and energizing anassociated integrated circuit 159 or other electrical device required bythe tag. The integrated circuit 159 can be disposed between the dipoleelements 156, 157 and wire bonded (not shown) to them in a conventionalmanner. The dipoles 160, 161 can also include a tuning stub for tuningtheir predetermined response frequencies and/or a holding bar 158 foruse in impedance matching. The dipole elements 156, 157 of the dipole163 are provided with respective antenna extensions 156 a, 157 a toprovide increased antenna length within the circular area available inthe circular substrate region 160 a.

All of the shapes of the dipole elements 156, 157 forming the dipoles160-163, as well as the shapes of any other dipoles suitable for acircular substrate 160 a, or any other dipole substrate geometry, can beeasily implemented by the tag fabrication process 120. Theirimplementation requires only the suitable patterns for the adhesivetransfer device 130 and the die cutter 134. Any additional features ofdipole security tags, such as the tuning stub 155, the holding bar 158,the extensions 156 a, 157 a or a fuse (not shown) can also be easilyimplemented using the tag fabrication process 120.

In addition to shapes such as the S- and Z-shapes, the stub or strip,the meandering, the bent coil and the overlapping shapes shown hereinfor illustrative purposes, an almost unlimited number of additionaldipole conductor shapes can be easily implemented using the tagfabrication process 120. For example, slot dipoles and matrix doubledipoles having four circularly spaced-apart dipole elements can beeasily made using the process 120. Furthermore, the conductor traceshapes that can be fabricated using the tag fabrication process 120 arelimited only by the technology available for producing the adhesiveimages or patterns corresponding to the shapes and for die cutting theconductive traces according to those adhesive images or patterns.

Further, in accordance with the tag fabrication process 120, a secondprocessing station 126 can be provided as can be seen in FIGS. 1, 4 and5. While the operations of the processing station 126 are describedherein in combination with selected processing stations for illustrativepurposes, it will be understood that the processing station 126 can beused with any, or no, other processing stations. Within the secondprocessing station 126, a second patterned adhesive layer 135 a can beapplied by a second adhesive transfer device 136. The second adhesivetransfer device 136 can be any type of adhesive transfer device known tothose skilled in the art, as previously described with respect to theadhesive transfer device 130.

The adhesive transfer device 136 can deposit an adhesive material 135 onselected portions of the surface 150 a of the substrate 150 or on asurface of the first conductive trace 132 a to form a second patternedadhesive layer 135 a. In an alternate embodiment, the second adhesivelayer 135 a can be disposed on both the substrate 150 a and the firstconductive trace 132 a. In another embodiment, the adhesive 135 a can bedisposed on any other suitable surface or surfaces over the substrate150 in addition to the substrate surface 150 a itself or the firstconductive trace 132 a. The second patterned adhesive layer 135 a canalso be disposed on the side of the substrate 150 opposite the firstpatterned adhesive layer 122 a.

As seen most clearly in FIG. 5, a second conductive foil 140 is appliedto the surface of the substrate 150 and/or on the surface of the firstconductive trace 132 a (hereinafter, the “surface area of the tag”), forexample, from an unwind roll (not shown). The material forming thesecond conductive foil 140 can be any conductive material, especially ametal such as aluminum or copper. In a preferred embodiment, aluminum isused because it is sufficiently conductive and relatively inexpensive.The second conductive foil 140 is provided with a dielectric layer 138.The dielectric layer 138 can be a flood coated dielectric layer formedon a surface of the second conductive foil 140, a separate sheet ofdielectric material applied to the second conductive foil 140 before orduring the tag fabrication process 120 or any other type of dielectriclayer.

When the dielectric layer 138 and the conductive foil 140 are applied tothe substrate surface 150 a and/or the surface of the first conductivetrace 132 a, the dielectric layer 138 adheres to portions of the surfacearea 132 a according to a pattern of the second patterned adhesive layer135 a. The dielectric layer 138 and the conductive foil 140 are thenpatterned by a die cutter 144 using the die cutter blades 143, whichpattern them according to the pattern of the second patterned adhesive135 a. The unused portions of the dielectric layer 138 and theconductive foil 140 are removed, for example, by a vacuum device forrecovery, as described earlier. The removal of the unused portions canoccur substantially simultaneously with and in-line with the patterningoperations performed using the die cutter 144.

The second conductive trace 140 a formed by the adhesive transfer device136 and the die cutter 144 can be the same shape as the first conductivetrace 132 a. It can be disposed on the substrate surface 150 a, theconductive trace 132 a, or both. Furthermore, one, both or neither ofthe conductive traces 132 a, 140 a, or any of the layers in the securitytag can be disposed in direct physical contact with the substrate 150,or any other area where the patterned adhesive layer 135 is disposed. Anelectrical connection can be provided between the conductive traces 132a, 140 a.

The adhesive transfer device 136 and the die cutter 144 cooperate toform the processing station 126 of the tag fabrication process 120.While the tag fabrication process 120 is described in detail in theembodiment having a single processing station 124 and the embodimenthaving two processing stations 124, 126, it will be understood that anynumber of processing stations 124, 126 can be provided in accordancewith the method of the invention. Furthermore, in one preferredembodiment of the invention, the processing stations 124, 126 can belocated on opposing surfaces of the substrate 150, and the structurefabricated by the tag fabrication process 120 can be built on theopposing surfaces of the substrate 150.

In an another embodiment of the tag fabrication process 120, theprocessing station 124 can provide a first patterned conductive trace132 a shaped as an inductive element, such as a concentric coil, and aplate of a capacitive element. In this embodiment, an adhesive image ofthe coil and the capacitor plate is disposed on the substrate surface150 a by the adhesive transfer device 130. The second patternedconductive trace 140 a can be a second plate of the capacitive element,wherein an adhesive image of the second plate is disposed on the firstpatterned conductive trace 132 a or any other suitable surface area bythe adhesive transfer device 136.

In this manner, a complete LC security tag can be formed on a singlesurface 150 of the substrate 150 by the tag fabrication process 120without the use of any photo-resist or etching operations. The onlymaterials required to fabricate the die cut structures produced by thetag fabrication process 20 are the substrate, the adhesive and theconductive foil. Alternately, both the first and second patternedconductive traces 132 a, 140 a can be formed as dipoles or any otherdevices which can be formed by patterning the conductive foils 132, 140.For example, the tag fabrication process 120 can be used to fabricatemultiple frequency tags such as those disclosed in U.S. Pat. No.5,510,769, entitled “Multiple Frequency Tag,” issued to Kajfez, et al.on Apr. 23, 1996.

Additionally, the process 120 can be performed without waste of theadhesive or conductive foil. The only adhesive used in the process 120is where the adhesive is actually required to form the conductor traces.Any conductor material cut away by the die cutters 134, 144 is easilyrecovered by a simple melting process.

In prior art security tags, the dielectric material disposed between theplates of a capacitor served as both the dielectric of the capacitor andthe structural element upon which the tag was fabricated. Furthermore,the dielectric material was required to withstand the harsh environmentof the photo-etch baths used in forming the conductor traces. Thesefactors placed serious constraints on the selection of dielectricmaterials.

In security tags fabricated using the tag fabrication method 120,however, the dielectric layer 138 between the plates of the capacitor isnot used as a structural element. Furthermore, the dielectric layer 138is not required to withstand a photo-etching process. Therefore, thematerial forming the dielectric layer 138 can be selected primarily forthe purpose of optimizing its dielectric properties, rather than for itsmechanical strength or its resistance to etchants.

This permits, for example, the selection of materials having higherdielectric coefficients than the materials previously used as capacitordielectrics in the fabrication of security tags. The use of materialshaving higher dielectric coefficients makes it possible to obtain apredetermined amount of capacitance within a smaller capacitor size.Smaller capacitor size permits the fabrication of smaller security tagsfor the same response frequencies. It also permits higher fabricationyields and lower tag costs.

Alternately, the use of higher dielectric coefficient materials makes itpossible to obtain an increased amount of capacitance within apredetermined area of a substrate 150. Increased capacitance within anLC security tag permits the fabrication of a tag having a predeterminedresonant frequency with less inductance. Fewer turns of the inductorcoils are required when there is increased capacitance in the tag. Thereduced number of turns in the inductor coils results in less unwantedcoil resistance. Security tags formed in this manner thus have a higherquality factor Q, because of the reduced resistance in the coils.Additionally, it is understood that the magnetic effects of opposingturns in the coils result in unwanted self-cancellation of the currentsin opposing turns of the coils. Therefore, coils formed using the tagfabrication process 120 and having fewer turns can have more efficientcoupling to their antennas.

Those skilled in the art will understand that the tag fabricationprocess 120 can be used to provide a plurality of security tags in acontinuous web of any size. For example, U.S. Pat. No. 5,614,278,entitled “Strip of Separable Labels or Tags Having a Display Surface forDisplay of Information Thereon,” issued to Chamberlain et al. on Mar.25, 1997, discloses tags supplied as a strip of consecutive separableunits that moves along a path of travel. U.S. Pat. No. 4,717,438,assigned to Monarch Marking Systems, Inc., discloses a method of makingtags wherein conductors are cut from a planar web of conductive materialin a continuous process. The cutting results in the formation of twospiral conductors which are thereafter positioned to provide resonantcircuits.

When the tag fabrication process 120 is used to provide a plurality ofsecurity tags in this manner, the adhesive transfer devices 130, 136 arepreferably rotatable devices, such as rotatable printing devices.Furthermore, those skilled in the art will understand that producers ofsecurity tags can decrease or eliminate the need to maintain inventorysince the tag fabrication process 120 permits tags to be created asneeded on demand.

Referring now to FIG. 8, there is shown the tag fabrication process 165.The tag fabrication process 165 is an alternate embodiment of the tagfabrication process 120. It will be understood that, as was shown inFIG. 1, when the die cutter 144 of the processing station 126 within thetag fabrication process 120 cuts through the conductive foil 140 and thedielectric layer 138, it is extremely important to avoid damaging theconductive trace 132 a and the substrate 150. Failure to cut to thecorrect depth during die cutting can cause tags produced by the tagfabrication process 120 to be defective. Additionally, when force isapplied during the die cutting operation the conductive trace 132 a orthe substrate 150 can be damaged by the force.

Therefore, as shown in FIG. 8, within the tag fabrication process 165,the processing station 182 can be substituted for the processing station126. The processing station 182 can be used to form circuit elementswhich can be electrically coupled to the conductive trace 132 a withoutperforming any further die cutting operations over the surface 150 a ofthe substrate 150, thereby removing the risk of damaging a tag during adie cutting operation.

In the processing station 182, a supply of precut conductive traces 170is applied to the tag fabrication process 165 for registration with theconductive traces 132 a using a carrier 174. In one preferred embodimentof the invention, the conductive traces 170 can be provided with a layerof adhesive dielectric 168 for adhering the conductive traces 170 to thesubstrate 150. In another embodiment, the adhesive dielectric 168 andthe conductive trace 170 can be applied in separate steps.

The conductive traces 170 can be adhered in this manner to theconductive traces 132 a, the substrate surface 150 a, or any othersurface on the substrate 150. This method can be used, for example, informing a dielectric and a plate of a capacitor. Any other known methodcan be used to form a capacitor dielectric between the conductive traces132 a, 170. For example, a dielectric material that is not an adhesivecan be laminated to the conductive traces 170. In such a case anadhesive layer can be provided between the dielectric material and theconductive trace 132 a.

The conductive traces 170 can be transferred to the substrate 150 by anyconventional technique known to those skilled in the art. For example,the well known rotary transfer device 172 can be used to transfer theconductive traces 170 from the carrier 174 to the substrate 150. Inanother example, well known windowing machines (not shown) of the typeused to apply transparent windows to mailing envelopes can be used.Regardless of what method is used to apply the conductive traces 170 tothe substrate 150, care must be taken to achieve the correctregistration of the conductive traces 132 a, 170. As previouslydescribed, small amounts of conductor misalignment produce largevariations in the capacitance and concomitant large variations in theresonant frequency of the resulting tags.

Referring now to FIGS. 9A and 9B, there are shown surface processingsystems 167, 171 which effect the tag fabrication process 120 of thepresent invention. It will be understood that the tag fabricationprocess 120 can be integrated into surface processing systems 167, 171or any other system for processing a surface of an item. In particular,the process 120 can be performed within, along with, or integrated into,any other type of process or processes in which printing of a surface,or any other processing or preparation of a surface, is performed. Forexample, within the surface processing system 167, a processing station164, having an adhesive transfer station 164 a and a die cutter 164 b,can perform the tag fabrication process 120 upon the surface 150 a whileintegrated with an integrated process 166 having integrated operations166 a and 166 b.

When the integrated process 166 and the tag fabrication process 120within the processing station 164 are integrated in this manner, it ispossible to conventionally print, for example, identifying, promotionalor instructional material upon a portion of the surface 150 a using theprocessing stage 166 a. Additionally, it is also possible to fabricate asecurity tag upon the surface 150 a using the processing station 164within the surface processing systems 167. It is then possible to printor perform some other operation upon a portion of the surface 150 ausing the processing stage 166 b.

The integrated process 166 can include any number of differingoperations, such as printing operations and lamination operations, aswell as multiple occurrences of a single type of operation. In oneembodiment, the processing station 164 can fabricate dipole elementssuch as the dipole elements 147, 148 of the dipole 146 a, or dipoleelements such as the dipole elements 151, 152 of the dipole 146 b andthe processing stage 166 b can insert the integrated circuit 145, 153and the wire 149, 151 to wire bond the integrated circuit 145, 153 tothe respective dipole elements. Furthermore, the processing station 164can include any number of adhesive transfer devices and die cutters.

When the integrated process 166 includes a number of differing stations,the individual operations of the tag fabrication process 120 can beperformed at any stage within the integrated process 166. Additionally,the various operations of the tag fabrication process 120 and theintegrated process 166 can be performed in any order required. Thus, therelative positions of the operations and the order of the operations setforth in the drawing are for illustrative purposes only and are notintended to limit the scope or the invention.

The ability to integrate a processing station 124, 126 performing thetag fabrication process 120 within other processes thus permitsmanufacturers to easily apply a security tag to items while the itemsare being manufactured, finished, packaged, shipped, and so forth. Forexample, a processing station 124, 126 can be inserted at a selectedpoint in a manufacturing process where an item is undergoing apreviously required printing or finishing step. In this manner, the itemcan be provided with a security tag at the selected point of theprocess, for a substantially insignificant cost beyond the cost of themanufacturing process itself, e.g., the incremental cost of including atag with other printed material is very low.

The operations performed by the processing stages 166 a and 166 b of theintegrated process 166 can also be any other operations such asscreening, plating, laminating, coating, finishing or processing thesurface 150 a in any manner. A printing process integrated with the tagfabrication process 120 in this manner can include flexographicprinting, gravure printing, printing by a letter pressing device, or anyother type of process for applying patterned substances includingadhesive substances to the surface of the substrate 150, as previouslydescribed.

The processing station 124 can also be integrated with an inspectionstation for performing a quality control process within a tagfabrication process such as the tag fabrication process 120. Forexample, such an integrated inspection station can perform a qualitycontrol process adapted to energize a tag at its predetermined frequencyfollowing the fabrication of the tag, measure the response signal of thetag to the applied energy, and determine whether the tag is workingproperly. The center frequency of the tag response signal, the qualityfigure Q of the tag response signal, the amplitude of the responsewaveform, or any other tag parameter or ratio of parameters can bemeasured in order to make such a determination. Thus, defective tagsfabricated by the tag fabrication process integrated with the qualitycontrol process can be located by the quality control process.Additionally, tags that are working correctly and tags that aredefective can be identified and counted separately. Inspection stationsfor performing quality control are discussed in further detailhereinbelow.

The ability to integrate a processing station 124, 126 with other typesof processes also permits a manufacturer to apply plural security tagsto an item being manufactured at a slight incremental cost. For example,in the surface processing system 171, after an operation 174 a of anintegrated process 174 is performed upon the surface 150 a, theprocessing station 182 can apply a first security tag to the surface 150a using the adhesive transfer station 182 a and the die cutter 176 b.Subsequently, for example, after the substrate is further processed by afurther operation 178 a with an integrated process 178, the processingstation 180 can apply a second security tag using the adhesive transferstation 180 a and the die cutter 180 b.

The first and second security tags applied to the substrate 150 need notbe identical tags. For example, one security tag can be an LC-basedsecurity tag and the other can be a dipole-based security tag.Additionally, the tags can both be RF tags, or both be UHF tags, thatrespond to different frequencies in the same frequency band. Amanufacturer of items using the tag fabrication process 120 also has theoption to apply security tags to selected percentages of the items beingmanufactured by merely turning the processing stations 164, 176, 180 onor off as items are being processed by the various integrated processes.For example, the manufacturer can select a process in which all, fiftypercent, none, or some intermediate percentage of items receivefabricated security tags.

Furthermore, the processing station 182 can be adapted to fabricate thedipole elements of a dipole on the substrate 150 and the integratedprocess 178 can be adapted to insert and bond the integrated circuits145, 153, 159 into their respective dipole elements. In an alternateembodiment, the integrated process 178 can be adapted to measure afrequency of the dipole and adjust a capacitance, for example, byadjusting a tuning stub 155 or by adjusting the amount of capacitance orinductance in some other manner. The capacitance of a tag can beadjusted by adjusting plate area, by adjusting a dielectric thickness inselected areas of the dielectric, by scratching a dielectric surface, byapplying a conductive ink or a solvent, by adjusting the registration ofthe plates, by squeezing capacitor plates together to compress thedielectric therebetween, or by any other means.

Additionally, the frequency of the tags can be adjusted by adjusting anyother tag parameters or values in addition to capacitance. Feedbacksystems of this nature can be used to bring the response frequencies ofthe security tag fabricated towards the center of its nominal range andthe number and magnitudes of the adjustments can determined andrecorded. Such a quality control method can be applied to any devicewithin the tag fabrication process 120.

In one preferred embodiment of the invention, the processing system 171can provide an item level association between: 1) an item levelidentification number disposed on an item or an object such as a packageor label having a substrate 150 with a surface 150 a, and 2) anautomatic identification number, or license tag, stored on a device suchas, for example, an RFID or EAS tag. In such an item level associationsystem 171, the integrated process 174 can print an optical marking suchas a bar code or any other visually perceptible indicia representativeof the item identification number on the surface 150 a. The marking canbe human readable or machine readable. The marking applied by theintegrated process 174 can thus encode the item level identificationnumber of the item being processed by the association system 171 in anymanner.

The integrated process 174 can print the marking representing the itemlevel identification number on the surface 150 a with or withoutapplying other indicia to the surface 150 a. Other indicia that can beapplied to the surface 150 a by the integrated process 174 or by someother integrated process along with the marking can include packageinformation or designs and labeling information.

Within the item level association system 171, the processing station 176fabricates or applies a marking comprising a circuit element such as atag circuit on the surface 150 a. The circuit element applied by theprocessing station 176 can be applied at any location on the surface 150a relative to the marking applied by the integrated process 174.Furthermore, the circuit element can be fabricated or applied in themanner previously described, or in any other manner known to thoseskilled in the art.

A circuit element applied in this manner can be, for example, a coil, acapacitor, a dipole or an integrated circuit element. Furthermore, thecircuit element can include a license plate identification number forautomatic identification of the circuit when the circuit element isinterrogated. In further alternate embodiments of the invention, themarking that includes the item level identification number and themarking that includes the automatic identification number can be appliedin the opposite order, or in combination with other surface processingoperations in any order.

Thus, in one preferred embodiment, both of the markings are disposed onthe surface 150 a before the markings are applied to the integratedprocess 178 within the item level association system 171. In thisembodiment, the integrated process 178 is advantageously adapted to bean association system 178. The association system 178 can include asystem for reading the marking applied by the integrated process 174 inorder to determine the item level identification of the item. Forexample, the association system 178 can include a bar code reader forinterrogating a bar code marking applied to the surface 150 a by theintegrated process 174 and provide a signal representative of the itemlevel identification number encoded by the bar code marking.

A circuit element interrogation device can also be provided within theassociation system 178 for interrogating the circuit element applied tothe surface 150 a by the processing station 176. The circuit elementinterrogation device within the association system 178 can thusinterrogate the tag on the surface 150 a to determine its automaticidentification number. The item level identification number and theautomatic identification number can be associated with each other andwith the item upon which they are disposed by the association system171. The associated information can be stored in a database and accessedin response to a later interrogation of one of the markings to determinethe identity of the item.

It will be understood that the method set forth for the item levelassociation system 171 can be extended to operate upon differentmarkings disposed on different items in order to determine relationshipsbetween the various markings and items. For example, a first associationcan be determined between an item level identification number and anautomatic identification number disposed on a first item, as previouslydescribed. A second association can be determined between the item levelidentification number and an automatic identification number on a seconditem. Thus, the first and second items can be associated with each otherby the item level association system 171.

Additionally, the markings disposed on either of the first and seconditems can be representative of either an item level identificationnumber or an automatic identification number. The different itemsbearing the various markings can be processed serially, in parallel orin any other manner. Furthermore, in another alternate embodiment one ormore markings can be applied to the surface 150 a before the substrate150 is received by the item level association system 171 and one or moremarkings can be applied to the surface 150 a within the item levelassociation system 171. It will be understood that some identifyinginformation for an item, (i.e. either its item level identificationnumber or its automatic identification number), may already be known inthe case where a marking is disposed on the surface 150 a prior to thetime that the surface 150 a is received by the identification system171. In this case it may only be necessary to perform one interrogationin order to determine the required association.

Additionally, a plurality of markings representative of item levelidentification numbers can be disposed on a surface 150 by a processsuch as the integrated process 174 within the item level associationsystem 171. Furthermore, a plurality of markings having automaticidentification numbers, such as those applied by the processing station176, can be applied to a surface 150 a within the item level associationsystem 171. Any of the markings applied in this manner can be associatedwith each other and with an item or items by the item level associationsystem 171.

A processing station 124, 126 for performing the tag fabrication process120 and a device performing an integrated process need not be standalone devices dedicated to performing their own operations. It is alsocontemplated that one or more processing stations 124, 126 can be builtinto a host device which can perform the integrated process orprocesses. It is also contemplated that a device performing one or moreintegrated processes can be built into a system for performing the tagfabrication process 120. For example, one or more processing stations124, 126 can be built into a host device, such as a printing device, atthe time the host device is manufactured. The resulting integratedsurface processing systems 167, 171 are thus adapted to print on thesurface of an item, and fabricate a security tag on the surface of theitem, as part of an integrated in-line process.

Additionally, a system performing the tag fabrication process 120 can beprovided as a component of a device or a part of a component of a deviceperforming an integrated function. For example, a processing station124, 126 can be built into a component for insertion into a host deviceperforming an integrated function, such as a processing station 124, 126adapted to function as a roller for insertion into a host printingdevice. The component or part of a component including the processingstation 124, 126 can be detachably secured to the host device or fixedto the host device.

In an especially advantageous preferred embodiment of the invention, aprocessing station 124, 126 can be integrated with a flexographicprinting device to fabricate security tags at speeds of at least twoorders of magnitude faster than conventional photo-etching fabricationprocesses. Furthermore, the ability to build a processing station 124,126 into a roller for insertion into a flexographic printing devicepermits the fabrication of security tags at this greatly increased speedand without the large investment that would be required to obtain a newprinting device manufactured with a processing station 124, 126 thereinfor performing the tag fabrication process 120.

The tag fabrication process 120 can be integrated with a process forpreparing a surface of substrates adapted to be associated with an itemto be monitored, in addition to the item itself. A surface processed bythe tag fabrication process 120 can be associated with an item to bemonitored by clipping or adhering it to the material of the item, byinserting it into the item or packaging containing the item, by merelyplacing it in the vicinity of the item or in any other manner. Forexample, the tag fabrication process 120 can be applied to pallets fortransporting items or packaging materials for containing an item oritems to be monitored; for example, to materials such as plastic, paper,cloth or cardboard, especially the cardboard of corrugated boxes.

When a surface processing system such as a surface processing system167, 171 is being operated, it is sometimes useful to determine how manytimes an individual processing station 164, 176, 180 is operated, ormore specifically, how many security tags are fabricated by the surfaceprocessing system 167, 171. Many different counting mechanisms are knownto those skilled in the art for making these determinations. Forexample, the number of rotations or other movements of a rotary adhesivetransfer device or a rotary die cutter can be counted using aconventional rotation counter. If a processing station 124, 126 isinserted into a roller of a printer such as a flexographic printer, thenumber of rotations of the roller can be counted. Additionally, thenumber of items processed by the surface processing system 167, 171,regardless of how many items receive a security tag, can be determinedby conventional suitable counting devices disposed at suitable locationswithin the integrated devices.

Referring now to FIG. 10, there is shown the billing model 200 fordetermining billing information for users of the tag fabrication process120. The costs for using the tag processing process 120 can bedetermined and billed to a user of the system 120 in many ways. Onemethod for billing the user is to include the costs of the fabricatingprocess 120 in a sale or rental of equipment adapted to perform theprocess 120. For example, a processing station 124, 126, along with anynumber of additional processing stations and integrated processes, canbe included within a flexographic printer purchased by a user in orderto fabricate security tags. Purchase of the equipment adapted to performthe tag fabricating process 120 can thus give the purchaser the right touse the purchased equipment to perform the tag fabricating process 120.

Alternately, the user of the tag fabricating process 120 can be billedon a usage basis, such as a per-tag-basis. A usage cost determined inthis manner can be either instead of or in addition to the foregoingcosts incorporated into the cost or the rent of the equipment. In orderto determine the usage costs in this embodiment of the billing models200, the number of security tags fabricated by the user of the process120 can be counted. For example, any conventional counter can beinserted into a roller or other device for performing the adhesivetransfer functions or the die cutting functions of a processing station124, 126. Alternately, the usage costs can be determined by monitoringthe amount of adhesive, conductor, substrate or any other resourcesupplied to a processing station 124, 126, such as electricity.Furthermore, the usage costs can be determined by monitoring any of theoperations of any integrated process, by measuring the time of operationof the tag fabricating process 120, the number of fabricated tags thatare operating correctly, or any other operation or method.

It will be understood that the methods set forth for determining theusage cost for billing a user of the tag fabrication process 120 are forillustrative purposes only and are not intended to be exhaustive. Forexample, in the embodiment of the tag fabrication process 120 in whichthe user selectably applies a security tag to a varying percentage ofthe items being processed by an integrated process, the costs can bedetermined on a per-item-basis, a per-tag-basis, or any other basis,including discounts based upon usage volume. Similarly, if a user isapplying plural security tags to items, either selectably or to all ofthe items, the costs can be determined on the same bases. In anotheralternate embodiment of the invention, wherein preformed circuitelements such as coils or plates are disposed on a substrate during thefabrication process, the number of such circuit elements supplied to thefabrication process can be counted. Alternatively, a user of the presentinvention can be required to purchase such preformed elements ormaterials from a predetermined seller in order to determine the numberof circuit elements used for purposes of obtaining billing information.

The output information of suitable counting an/or measuring deviceswithin a processing station 202, an integrated process 203 and/or anyother related monitoring devices 206 is applied to an event counter 208for obtaining a measure of the amount of usage of the tag fabricationprocess 120. The usage component of the costs within the billing models200 is provided at the output of the event counter 208 and applied to aprocess usage component block 210.

Additional costs, if any, are also determined within the billing models210. For example, costs due to any purchase or rental agreements can bedetermined at block 212 and any additional agreed upon licensing costscan be determined at block 214. The licensing can be licensing of tagdesigns, tag design tools or any other properties, including know-how.Any other additional costs agreed to can also be determined at thispoint. The output of the blocks 210, 212 and 214 are applied to theinput of the summation device 216 to provide the determined billing forthe tag fabrication process 120.

Referring now to FIG. 11, there is shown a schematic representation of asurface processing system 250 including a color printing press 253 and atag fabrication processing station 272 for applying color ink patternsand circuit elements to a surface of a substrate 251 to fabricatesecurity tags according to the present invention. The substrate 251 canbe any suitable substrate material. For example, the substrate 251 canbe plastic, paper or a cardboard, preferably a corrugated cardboard.Within the printing press 253, cyan 252, magenta 254, yellow 256 andblue 258 inks are applied to a surface of the substrate 251 in order toprovide the printed colored patterns on the surface thereof. Thesubstrate 251 can be flipped over at turnover point 270 of the surfaceprocessing system 250 in order to permit the remaining operations of thesurface processing system 250 to be performed on the surface of thesubstrate 251 opposite the surface to which the color pattern is appliedby the printing press 253.

Within the tag fabrication station 272, a patterned adhesive can beapplied to a surface of the substrate 251 by an adhesive applicationdevice such as the adhesive transfer device 274. A windowing machine 278can be provided within the surface processing station 250 in order toplace preformed circuit elements, for example, capacitor plates,antennas or coils including nested coils on the surface of the substrate251. The windowing machine 278 can be the conventional type of windowingmachine well known by those skilled in the art for placing, for example,cellophane windows on envelopes using a transferring vacuum drum. Theuse of a windowing machine 278 is especially advantageous within thesurface processing system 250 because it permits the placement ofcircuit elements of many differing sizes and shapes upon the substrate251 without making substantial changes to the tag fabrication station272.

Furthermore, the use of a windowing machine 278 permits the fabricationprocess of the station 272 to be easily changed from one size or shapeof circuit element to another. For example, using a windowing machine278, it is possible to very easily switch from a fabrication processrequiring one inch strips to a process requiring three inch strips, byproviding a continuous strip of conductive foil which is cut to therequired size and placed at the required location by the vacuum drum foreach individual circuit. It is possible to easily switch from one shapeof circuit element to another by merely applying separate pieces ofcircuit elements of differing shapes to the windowing machine asrequired, for example by disposing the circuit elements on a carrier inorder to apply them to the windowing machine 278.

A die cutter 280 within the surface processing system 250 can then beused to cut around the shape and the waste produced thereby is removedat the waste removal station 282. This results in a substrate 284carrying a semi-finished product such as, for example, coils includinginductor coils, capacitor plates or antennas.

Referring now to FIGS. 12, 13A and 13B, there is shown an input stage288 of a surface processing system for fabricating security tagsaccording to the present invention, as well as plan and cross-sectionalviews of a carrier 292 for carrying a supply of circuit elements 300 tothe input stage 288. The circuit elements 300 can be, for example,capacitor plates, coils, antennas or fuses for fabricating securitytags, including RFID security tags. The input stage 288 can also receivea semi-finished product, such as the semi-finished product disposed onthe carrier 284 provided by the surface processing system 250.

The carrier 292 and the carrier 284 are applied to a hot stamp coilsaver 296 within the input stage 288. The circuit elements 300 disposedon the carrier 292 can thus be applied to the circuit elements disposedon the carrier 284 to form resonant circuits for security tags.

The circuit elements 300 are preferably disposed as close as possible toeach other on the carrier 292 in order to conserve space. The motion ofthe carrier 284 and/or the motion of the carrier 292 into the hot stampcoil saver 296 are controlled using servo motors (not shown) in order toprovide the proper registration between the circuit elements on thecarrier 284 and the circuit elements on the carrier 292. In oneapplication of the input stage 288, capacitor plates can be heat sealedonto coils using the rollers 298 within the hot stamp coil saver 296when proper registration is achieved. Heat can be applied in the sameshape as the circuit elements 300.

In the preferred embodiment of the invention, the circuit elements 300can be adhered to the carrier 292 by an adhesive layer 304. A furtheradhesive layer 306 can be provided on the opposite surface of thecircuit elements 300 in order to assist in bonding the circuit elements300 to, for example, inductor coils. It will be understood that theadhesive between the circuit elements 300 and the inductor coils can beprovided on the surface of the circuit elements 300, on the surface ofthe inductor coils, or on both surfaces. Furthermore, it will beunderstood that the adhesive between the circuit elements 300 and thecoils can be an adhesive dielectric.

Referring now to FIG. 14, there is shown a surface processing system 320for fabricating security tags in accordance with the present invention.A die cutter 328 within the surface processing system 320 can receive aconductive foil 324 and form circuit elements, such as the circuitelements 300 (see FIGS. 13A and 13B). Thus, the die cutter 328 canproduce the previously described carrier 292. A waste take up roll 326can remove the waste conductor foil produced by the die cutting processperformed by the die cutter 328. It will be understood that the wasteconductor foil on the waste take up roll 326 can be recycled into thedie cutter 328 in order to more efficiently use the conductor foil 324.

The carrier 284 and the carrier 292 are applied to the hot stamp foilsaver 296 of the surface processing system 320, substantially aspreviously described with respect to the input stage 288. The hot stampfoil saver 296 presses the carriers 284, 292 together, hot stamping thecircuit elements 300 disposed on the carrier 292 onto the ones disposedon the carrier 284, as previously described, thus, providing the carrier294 having resonant circuits suitable for use in security tags.

The carrier 294 can then be applied to a deactivation station 336 toprovide capability and/or test deactivation effectiveness within thecircuits formed by the hot stamp foil saver 296. A preferreddeactivation point can be created by scratching one or both sides of thedielectric, for example using a mechanical process, whereby two tracesare brought closer together. The mechanical process can use a dimplingprocess to bring two conductive traces relatively closer to each otherat a selected point or any other mechanical technique. Any tests ofdeactivation effectiveness can be performed on a predeterminedpercentage of the circuits, for example, one circuit out of a thousand.The percentage of circuits which do not deactivate can thus bedetermined. A weld station 340 can be provided within the surfaceprocessing system 320.

An inspection of the circuits formed on the carrier 294 by the hot stampfoil saver 296 can be performed at the inspection station 344. Theinspection station 344 can test any circuit parameter or parametersdesired. The inspection performed by the inspection station 344 can beused to identify defective circuits disposed on the carrier 294, as wellas to perform any metering functions desired. Additionally, theinspection station 344 can be used to provide feedback to earlier stagesof the surface processing system 320, or to provide a feed forwardsignal to later stages, for adjusting and controlling any circuitparameters desired. In addition to being used to correct circuits beingformed by the surface processing system 320 (e.g. by changingregistration or trimming) the inspection station 344 can be used to markany defective circuits it locates, or even to repair such defectivecircuits. A die cutter 346 can also be provided.

In an alternate embodiment of the invention (not shown), the surfaceprocessing station 320 can be modified by removing the die cutter 328and the hot stamp foil saver 296, and substituting in their place an inline printing station for applying a conductive ink to the circuitelements disposed on the carrier 284. In this manner, it is possible toform, for example, a plate of a capacitor over a coil disposed on thecarrier 284 from the conductive ink.

The metering functions performed within the inspection station 344 orany other operations within the system 320 can be coupled to acommunication channel 250 in order to permit monitoring of a tagfabrication process being performed by a system such as the surfaceprocessing system 320. Monitoring by way of the communication channel250 can be performed at a location within the system 320, external tothe system 320 at another location in a plant or installation where thesystem 320 is disposed, or at a location remote from the location wherethe system 320 is disposed.

The communication channel 250 can be an internet connection, a broadcastlink such as a radio frequency link or a microwave link, a telephoneconnection, an electrical wire, an optical link, or any otherunidirectional or bidirectional system for communicating data. Thus, thequality as well as the quantity of the tags being fabricated by thefabrication process such as the processes performed by the surfaceprocessing system 300 can be monitored from any location.

Data collected in this manner by the surface monitoring system 320 canbe applied as an input to the billing model 200 for determining billinginformation. Thus, the communication channel 250 can permit billinginformation to be determined locally or remotely. Additionally, sincethe information transmitted by the surface processing system 320 caninclude center frequency, quality factor Q, signal amplitude anddeactivation effectiveness as well as any other parameter, theinspection station 344 can permit a licensor of the tag fabricationprocess of the present invention to monitor the quality as well as thequantity of tags being fabricated by a licensee.

Referring now to FIG. 15, there is shown the capacitor 360 which issuitable for use in a security tag. The capacitor 360 can be formedaccording to any one of the preferred embodiments of the presentinvention or by any other fabrication process known to those to thoseskilled in the art. The capacitor 360 includes a bottom plate 372, adielectric layer 370 and a top plate 366. The bottom plate 372 can bedisposed upon a surface 362 a of a substrate 362. Furthermore, thebottom plate 372 can be disposed directly upon the surface 362 a or uponone or more intervening layers disposed between the bottom plate 372 andthe surface 362 a.

In prior art, it is known to achieve alignment of the plates 366, 372 inmany ways. For example, alignment indicia on a package or substrate canbe used, thereby allowing for a fiducial or barcode type structure.However, when fabricating capacitors, failure to correctly align the topand bottom plates of the capacitor, for example due to manufacturingvariations, could result in substantial variations in the value of thecapacitance produced. Variations in the value of the capacitance resultin unwanted shifts in the resonant frequency of a circuit. Themanufacturing variations can be due to differing design considerations,the tolerances of a design process, or other factors.

In a preferred embodiment of the invention, the top plate 366 of thecapacitor 360 is formed substantially small compared to the bottom plate372. Additionally, the top plate 366 is disposed at a location offsetfrom an edge of the bottom plate 372 in at least one planar dimension ofthe surface plane of the bottom plate 372. Preferably, the top plate 366is offset from the edges of the bottom plate 372 in both orthogonalplanar directions of the bottom plate 372. The magnitudes of the offsetor offsets are selected according to the expected variations in thepositioning of the top plate 366 relative to the bottom plate 372.

In the preferred embodiment, the magnitude of the offset is selectedsuch that at least a portion of the bottom plate 372 continues to bedisposed below the entire surface area of the top plate 366 when thepositioning of the top plate 366 over the bottom plate 362 is within theexpected variations. In this configuration, the entire surface of thetop capacitor plate 366 faces an opposing area of the bottom plate 372as long as the variations in the positioning are within the expectedrange. Thus, the effective capacitor plate area for determining thecapacitance of the capacitor 360 remains substantially equal to the areaof the top plate 366 regardless of variations in the alignment of theplates 366, 372. This results in the value of the capacitance of thecapacitor 360 being substantially unchanged due to such variations inthe relative alignment of the plates 366, 372.

The plate 366 is described herein as the top plate of the capacitor 360and the plate 372 is described as the bottom plate for illustrativepurposes only. It will be understood by those skilled in the art that alower plate of a capacitor can be formed substantially smaller than atop plate, and preferably offset from the edges of the larger plate inat least one planar direction in order to obtain the advantageousresults of the invention. Furthermore, it will be understood that theplates 366, 372 can be disposed on opposing sides of any dielectricmaterial, such as the opposing sides of the substrate 362.

It will be understood that the word “security” in security tag isbroader than a tag for providing security against theft. The tag can beany tag providing a signal to indicate its presence or other informationabout itself or an item with which it is associated for any purpose.Furthermore, the method of the invention can be used to fabricate anycircuit or circuit element and is not limited to circuits within tags.

While the invention has been described in detail and with reference tospecific examples thereof, it will be apparent to one skilled in the artthat various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

1.-47. (canceled)
 48. A method of making a plurality of transponders ona high speed continuous printing line comprising the steps of: a.applying a flowable material in respective predetermined patterns on acontinuously moving carrier to form respective electrically conductivetraces, each of said electrically conductive traces making up at least aportion of a respective antenna; and b. securing respective integratedcircuit chips to said respective antennas without stopping the movementof said carrier.
 49. The method of claim 47, wherein the flowablematerial comprises an adhesive and wherein said forming of each saidelectrically conductive traces comprises applying an electricallyconductive foil to said adhesive and removing portions of said foil toleave a respective one of said electrically conductive traces.
 50. Themethod of claim 48, wherein said carrier comprises a substrate.
 51. Themethod of claim 50, wherein said method additionally comprises the stepof: c. printing visible indicia on said substrate without stopping themovement of said substrate to result in the production of plural items,each of said items including a respective one of said transponders andrespective visible indicia.
 52. The method of claim 50, wherein saiditems comprise packaging for a product and/or labeling for a productand/or promotional materials for a product.
 53. The method of claim 49,wherein said carrier comprises a substrate.
 54. The method of claim 53,wherein said method additionally comprises the step of: c. printingvisible indicia on said substrate without stopping the movement of saidsubstrate to result in the production of plural items, each of saiditems including a respective one of said transponders and respectivevisible indicia.
 55. The method of claim 54, wherein said items comprisepackaging for a product and/or labeling for a product and/or promotionalmaterials for a product.
 56. The method of claim 48, wherein theflowable material comprises a electrically conductive ink.
 57. Themethod of claim 48, wherein said carrier comprises a substrate.
 58. Themethod of claim 57, wherein said method additionally comprises the stepof: c. printing visible indicia on said substrate without stopping themovement of said substrate to result in the production of plural items,each of items including a respective one of said transponders andrespective visible indicia.
 59. The method of claim 58, wherein saiditems comprise packaging for a product and/or labeling for a productand/or promotional materials for a product.